Brandon J. answered 07/25/22
High School Math Tutor
Each of those outcomes you described is equally likely (1/8). So for each shake, the probability of a 6 is 1/8, the probability of a 7 is 3/8, the probability of an 8 is 3/8, and the probability of a 9 is 1/8.
Therefore, the probability of 7,7,7,7,7,9 is equal to (3/8)(3/8)(3/8)(3/8)(3/8)(1/8) = 243/262144